Manhole-cover



J. H. THOMSEN.

MANHOLE COVER.

APPLICATION HLED APR. 19. 1920.

1,388,492 Patented Aug. 23, 1921.

2 SHEETS-SHEET I.

J. H. THOMSEN.

MANHOLE COVER.

APPLICATION FILED APR-19, 1920 1,388,492. Patented Aug. 23, 1921.

2 SHEETSSHEET Z.

15 u vmewfoz J Theme/2,

ado rm m1 UNITED STATES PATENT OFFICE.

JOHN H. THoMsEN, or nnvnnronr, IOWA.

MANHOLE-COVER.

Figure 1 is a top plan View of the improved 1 cover,

Fig. 2 1s a vertlcal section,

Fig. 3 is a bottom plan view of the cover plate,

Fig. 4 is a longitudinal vertical section through the cover,

Fig. 5 is a side view of one of the latches,

F ig. 6 is a perspective view of the releasing device.

The present embodiment of the invention is shown in connection with a man hole 1 of usual construction, and the cover is in the form of a plate 2 having a central opening encircled by an upwardly extending rib 8. This rib is internally rabbeted at its top as shown at 4, to receive the cover plate 5, which fits within the rabbet.

Referring to Fig. 4: it will be seen that the rib 3 has an outwardly extending flange 5 at its top, so that a tongue of concrete 6 or other paving material may fit between the flange 5 and the cover 2. The cover 2 has openings 7 and upwardly extending pins 8 for engaging with the cement or other paving material to hold the same in place.

A pair of annular ribs 8 and 9 is provided I on the underface of the cover plate 5,the said f'ribs being coaxial and spaced apart from each other, and a series of pairs of latch supporting bars 10 is supported by the r1b s, the members of the pairs being pivoted 1n openings in the rib 8 as indicated at 11, and having their inner ends engaging openings in the rib 9.

Referring to Fig. 3 it will be seen that the members of each pair contact at their inner ends normally, and that each of the said members has an outwardly bent portion 12 at its outer end. Each of these outwardly bent portions carries a latch 18, and each of these latches has an inwardly extending pin 14.

A coil spring 15 is arranged between the latches of each pair of latch bars, and these springs act normally to force the outer ends of the members of the pair apart, the springs encircling the pins 14.

Specification of Letters Patent.

Application. filed. April19, 1920. Serial No. 374,944.

Patented Aug. 2-3, 1921.

These latches 13 are adapted to engage beneath catches 16 on the inner surface of the rib 3 to lock the cover plate 5 in place on the man hole. As shown in Fig. 5 the latches and the catches have cooperating beveled surfaces for engaging when the cover plate is pressed down into the rabbet to move the latches inwardly to permit them to pass the catches. As soon as the catches are passed by the latches, the springs will force the lat'zches outward beneath the catches.

Means is providedlor manually forcing said latch carrying bars apart at their inner ends, to contract the latches to release them from. the catches. Said means comprises a cross 17 which has at each end of each arm a depending wedge shaped lug l8, and these outer ends carrying the latches will be drawn together, to cause the latches to release the catches.

A rod 20 is mounted to slide through a central opening in the cross, and this rod is provided at each end with a cross head 21-22 respectively, the former cross head serving as a handle while the latter serves as a key to lock the rod to the cover plate. The cover plate has an opening 23 at its center shaped to fit and receive the rod and the cross head 22, and it will be evident that when the said cross head is inserted through the opening and the rod is turned to bring the cross head across the opening, the rod will be locked to the cover plate. Now the cross is forced downward to release the latches, and by means of the handle 21 the rod and the cover plate may be lifted from the rabbet.

The improved cover plate is designed to have its upper surface flush with the paving as shown in Figs. 2 and 4. Referring to Fig. 2, it will be seen that each of the plates 2 has on its underside and near its corners depending lugs 24. These lugs 24: are adapted to engage in the corner openings 7 of another plate, to nest the said plates during transportation. The studs 24. on each plate fit into the opening of the other plate, and the studs of each plate are hollow, the cor- 'ner openings registering with the hollow studs so that they will receive the vstuds of another plate.

The cover plate 5 has four openings 25, which permit the passage of the wedge shaped lugs 18 of the releasing device, and these openings are in register with the notches 19 of the latch bars v a a In use when the plate is built into the pavement as shown in Figs. 1 and 2, the pavement is firmly locked to the cover by means of the pins and openings and that tongue of paving material which extends between the flange5 and the body of the cover. In. placing the cover plate it is only necessary' to force it down into the rabbet4.l To

release the cover plate the tool shown in Fig.6 is made use-of. a

claim a a 1'. 'A man hole comprising a coverplate having inner and outer spaced annular ribs formedon the side, spaced pairs-of radial arms having their intermediate portions extended through and turned into said outer ribs, said innerribs being provided with openings slidably receiving the inner portions of said pairs of arms, pairs of latch bars carried b the other end of said pairs of arms, and colled springs confined between the arms of said pair of arms for separating the outer portions of the arms in each pair and urging the latch bars outwardly.

2. A man hole comprising a cover plate having inner and outer spaced annular ribs formed on the side, spaced pairs of radial arms having their intermediate portions extended through and turned into said outer ribs, said inner ribs being provided with openings slidably receiving the inner portions of said pairs of arms, pairs of latch bars carried by the other end of said pairs of arms a coiled spring confined between the arms of said pair of arms forseparating the outer portions of the arms in each pair and urging the latch bars outwardly the inner portions of said pairs of arms being provided with notches, and a key adapted for insertion into said notches for separating the inher portions of the arms.

JOHN H. THOMSEN. 

